JP2003345120A - Developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure the smooth supply of toner to a developing roller for a long time to make obtainable high image quality. <P>SOLUTION: This developing device 30 carries out development by supplying non-magnetic single component toner 32 from the developing roller 33 to an electrostatic latent image formed on the external circumferential surface of a photosensitive drum 21. The toner 32 is supplied in a positively electrified state, from a supply roller 34 to the developing roller 33 within a toner container 31. Positive DC bias voltages are supplied to the developing roller 33 and the supply roller 34 from DC power sources 35 and 36, respectively. A large number of threads 40 are attached to the external circumferential surface of the core 41 of the supply roller 34. The leading ends of the threads 40 come into contact with the surface of the developing roller 33. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for supplying a developer to an electrostatic latent image so as to make it visible for image formation by an electrophotographic method, and more particularly, a supply device for supplying the developer to a developer carrier. Regarding the part related to the roller.

[0002]

2. Description of the Related Art Conventionally, in a copying machine, a printer, a printing machine, a facsimile machine or the like for forming an image by an electrophotographic method, a powdery dry developer called toner is used to form an image on an image carrier. The electrostatic latent image is developed and visualized.

FIG. 14 shows the structure of a typical image forming apparatus. A photoconductive insulator layer is formed on the surface of the photosensitive drum 1, which is an image bearing member, and usually exhibits electrical insulation, and a portion irradiated with light exhibits conductivity. The photosensitive drum 1 rotates in the rotation direction 1a, and a charging device 2 is provided facing the outer peripheral surface of the photosensitive drum 1 in order to charge the surface thereof. The developing device 3 is disposed downstream of the charger 2 with respect to the rotation direction 1 a. On the downstream side of the developing device 3, the recording paper 4 contacts the outer peripheral surface of the photosensitive drum 1. A transfer device 5 is provided on the opposite side of the photosensitive drum 1 with the recording paper 4 interposed therebetween.
Are arranged. With respect to the rotating direction 1a, the cleaning device 6 is provided on the downstream side of the contact portion with the recording paper 4 and on the distillation side of the charger 2.
Are placed. The recording sheet 4 is conveyed to the fixing device 7 after coming into contact with the photosensitive drum 1. The fixing device 7 is provided with a heating roller 8 and a pressure roller 9, and presses the recording paper 4 by sandwiching it and heating it.

In the electrophotographic reversal development, first, the outer peripheral surface of the photosensitive drum 1, which is an image carrier, is uniformly charged by the charger 2. When light irradiation 10 is performed on the charged outer peripheral surface of the photosensitive drum 1, the portion that receives the light irradiation 10 becomes conductive and the electric charge disappears, and the portion that does not receive the light irradiation 10 is charged. As it continues, an electrostatic latent image is formed. The developing device 3 supplies the charged toner. When the charging polarity of the toner is set to be the same as the charging polarity of the photosensitive drum 1, the toner selectively adheres to the portion where the charge has disappeared by the light irradiation 10, and the development with the toner is performed. The transfer device 5 performs corona discharge with a polarity opposite to the charging of the toner to generate a suction force for transferring the toner on the outer peripheral surface of the photosensitive drum 1 onto the recording paper 4. The toner contains a binder resin, which is melted by heating and pressurizing the fixing device 7 to fix the toner transferred onto the recording paper 4.

The developing device 3 stores the toner 12 in the toner container 11. Toners, which are dry developers used for electrophotographic image formation, include non-magnetic one-component systems, magnetic one-component systems, and two-component systems. In the case of the non-magnetic one-component toner 12, the developing roller 13 as a developer carrying member is provided at the outlet of the toner container 11, the toner 12 is attached to the outer peripheral surface of the developing roller 13, and the toner is directly attached to the outer peripheral surface of the photosensitive drum 1. Contact. In order to efficiently attach the toner 12 in the toner container 11 onto the outer peripheral surface of the developing roller 13, a supply roller 14 is provided in the toner container 11. The supply roller 14 is in contact with the developing roller 13 while the toner container 1
The toner in 1 is agitated and moved to the developing roller 13. The toner 12 is charged to, for example, a negative polarity due to mutual friction during stirring. In order to smoothly move the toner 12, the developing roller 13 and the supply roller 14 are provided with conductivity in a state of having higher electric resistance as compared with a metal conductor, and the DC power supplies 15 and 16 provide negative polarity. DC bias voltages of are respectively given. Regarding the absolute value of the DC bias voltage, the supply roller 14 has a developing roller 13
Is set to the same potential or higher. The polarity of the DC bias voltage of the developing roller 13 is the same as the charging polarity of the photosensitive drum 1.

[0006]

In the developing device 3 using the non-magnetic one-component toner 12 as shown in FIG.
Toner container 1 via developing roller 13 and supply roller 14
The toner 12 in 1 is supplied. If the toner 12 is not properly supplied to the developing roller 13, a defective image is developed. Although the conventional supply roller 14 has a surface layer made of, for example, rubber, it is difficult to maintain a stable contact state with the developing roller 13 for a long period from the initial stage. Therefore, there is a demand for a developing device capable of stably forming a high quality image for a long term.

An object of the present invention is to provide a developing device capable of smoothly supplying toner to an image carrier and maintaining high image quality for a long period from the initial stage.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to a developer carrier for developing an electrostatic latent image with a non-magnetic one-component developer for image formation by an electrophotographic method, and a developer carrier. In a developing device including a supply roller that supplies an agent, the supply roller includes a roll-shaped core material, and one or a plurality of thread materials that are planted on an outer peripheral surface of the core material and have a tip contacting a developer carrier. And a developing device.

According to the present invention, since the image is formed in the electrophotographic system in which the electrostatic latent image is developed with the non-magnetic one-component type developer, the image defect due to the supply of the developer onto the developer carrying member is prevented. Therefore, it is possible to realize a supply roller capable of maintaining high image quality for a long period from the initial stage. The supply roller supplies the developer onto the surface of the developer carrier having a predetermined surface roughness and a predetermined hardness. In the supply roller, a plurality of thread materials are planted on the outer peripheral surface of the roll-shaped core material, and the surface of the thread material contacts the surface of the developer carrier, so that the electric field between the developer carrier and the supply roller is increased. , And the conditions such as the speed ratio between the developer carrier and the supply roller, the nip width (bite amount), and the like, the developer is supplied from the supply roller to the developer carrier, and the supplied developer has a predetermined amount. The developer is regulated to a predetermined developer layer thickness by the developer regulating member, and the developer whose layer thickness is regulated can be used for developing the electrostatic latent image bearing member in a developing region with a predetermined electric field.

Further, in the present invention, the thread material is flocked on the outer peripheral surface of the core material by an electrostatic flocking method, and the length of the thread material is in the range of 0.5 mm or more and 3 mm or less. Is characterized by.

According to the present invention, the thread material is flocked on the outer peripheral surface of the core material by the electrostatic flocking method, and the length of the thread material is
The range is 0.5 mm or more and 3 mm or less. When the length of the thread material is long, the density of the thread material implanted by the electrostatic flocking method is reduced, and when the length of the thread material is short, the electrostatic flocking is performed. Since the density of the thread material planted by the method increases, the density can be adjusted by the length of the thread material.

Further, in the present invention, the yarn material is characterized in that the single yarn decitex is in the range of 1 decitex or more and 10 decitex or less.

According to the present invention, the range of the single yarn decitex of the yarn material is set to 1 decitex or more and 10 decitex or less, and an appropriate contact state can be obtained.

Further, in the present invention, the thread material is electrically conductive and electrically conductive to the core material.

According to the present invention, since the thread material is electrically conductive and also electrically conductive to the core material, an electric charge can be given to the developer which comes into contact with the thread material.

Further, in the present invention, the yarn material has a single yarn resistance value in the range of 10 ⁵ Ω / cm or more and 10 ¹² Ω / cm or less.

According to the present invention, the single yarn resistance value of the yarn material is 10
Since it is in the range of ⁵ Ω / cm or more and 10 ¹² Ω / cm or less, it is possible to give an appropriate electric charge to the developer that comes into contact with the thread material.

Further, in the present invention, the yarn material is a yarn produced by a composite spinning method.

According to the present invention, since the thread material is manufactured by the composite spinning method, it is possible to appropriately impart conductivity and the like.

The present invention further includes a power source for applying a voltage to each of the developer carrying member and the supply roller, and the difference between the voltage applied to the developer carrying member and the voltage applied to the supply roller is 0 V or more. It is characterized in that the range is 350 V or less.

According to the present invention, a voltage is applied from the power source to the developer carrying member and the supply roller, and the difference between the applied voltages is kept within a certain range, so that the developer can be stably supplied.

Further, in the present invention, in the developer carrying member, a portion in contact with the supply roller is moved to develop the electrostatic latent image, and the supply roller is moved with respect to a moving speed of the developer carrying member. Further, it is characterized by further including a rotating mechanism for rotationally driving so that the speed ratio of the tip portion of the thread member is in the range of 0.5 times or more and 2.0 times or less.

According to the present invention, in the contact portion between the developer carrying member and the supply roller, the speed ratio of the tip portion of the thread material of the supply roller to the moving speed of the developer carrying member is 0.5. Since the supply roller is rotationally driven by the rotating mechanism so as to be in the range of not less than twice and not more than 2.0 times, it is possible to adjust the supply state of the developer also by the speed ratio and improve the image quality.

Further, in the present invention, in the supply roller, the amount by which the thread material is pushed into the surface of the developer carrying member is −0.1 mm or more with respect to the developer carrying member, and is 0.7 mm.
It is characterized by the following range.

According to the invention, on the surface of the developer carrying member,
Since the thread material of the developing roller is pressed in the range of −0.1 mm or more and 0.7 mm or less, the developer can be smoothly supplied to the developer carrier.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an electrophotographic image forming apparatus 2 including a developing device according to an embodiment of the present invention.
The structure of the main part of 0 is shown. The surface of the outer peripheral surface of the photosensitive drum 21, which is on the image carrier, is positively and uniformly charged by the charger 22. After the electrostatic latent image is formed by the light irradiation system 23, it is developed by the developing device 30. The electrostatic latent image is formed by irradiating the outer peripheral surface of the photosensitive drum 21 with light by the light irradiating system 23. The light irradiation system 23 performs light irradiation by modulating and irradiating laser light or light from a light source such as a light emitting diode (LED), or by optically guiding reflected light from the surface of the copy document.

The developing device 30 stores a dry non-magnetic one-component toner 32 in a toner container 31 and supplies it to the photosensitive drum 21 via a developing roller 33 which is a developer carrier.
The developing roller 33 has conductivity, is softer than the outer peripheral surface of the photosensitive drum 21, and is formed of a rubber-based material having elasticity. In the toner container 31, there is also provided a supply roller 34 which agitates the toner 32 to charge it to a positive polarity and supplies it to the developing roller 33. Developing roller 33 and supply roller 3
A DC bias voltage having a positive polarity is applied to each of the DC power sources 35 and 36. The layer thickness of the toner 32 attached to the outer peripheral surface of the developing roller 33 is regulated to be thin by the blade 37. The blade 37 is made of a hard rubber-based material having conductivity, and a bias voltage is applied by a DC power supply 38. In the supply roller 34 of this embodiment,
A large number of thread members 40 are planted on the outer peripheral surface of the core member 41.

FIG. 2 shows a schematic structure of the supply roller 34 shown in FIG. 2 (a) is a front sectional view, FIG.
(B) shows a state of a side sectional view. Core material 41
Is electrically conductive by a roller made of metal such as iron, and is rotatably supported at both ends. On the surface of the core material 41,
A flocked layer of the thread material 40 formed by the electrostatic flocking method is formed.
The flocked layer is formed by adhering the base end sides of many thread members 40 to the surface of the core member 41 with an adhesive agent 42.

FIG. 3 shows the principle of forming a flocked layer of the thread material 40 by the electrostatic flocking method. For example, when a radial electric field is generated around the core material 41 and the thread material 40 cut into a certain length is adsorbed, the thread material 40 can be radially attached around the core material 41 along the electric field. . The adhesive material 42 is applied to the surface of the core material 41, and the adsorbed thread material 40 can be attached to the surface of the core material 41, and the flocked layer can be easily formed.

That is, by using the thread material 40 cut into a predetermined length, the thread material 40 is formed on the outer peripheral surface of the roller-shaped core material 41 by the electrostatic flocking method while rotating the core material 41 around the axis. Flock. The thread material 40 can be flocked to the core material 41 regardless of whether it is an electrically insulating material or an electrically conductive material, and an insulating adhesive or a conductive adhesive agent is used for adhesion to the core material 41. The thread material 40 and the core material 41 are bonded by using. As the adhesive, a water-based acrylic emulsion adhesive, a urethane adhesive, or a polyester hot melt adhesive can be used. To provide conductivity, a conductive material such as silver paste is bonded. Knead into the agent.

When used as the supply roller 34 shown in FIG. 2, the thread material 40 preferably has conductivity. When conductivity is required, the thread material 40 forming the flocked layer can be used by imparting conductivity to nylon fibers or acrylic fibers. When such a supply roller 34 is used, the speed ratio θ between its peripheral speed and the peripheral speed of the developing roller 33 is set to 0.5 to 2.0. Even if the thread material 40 needs conductivity, the conductivity can be adjusted by combining the conductive thread and the electrically insulating thread and changing the ratio.

4 and 5 show a thread material 4 having conductivity.
Examples of conductive fibers that can be used as 0 are shown below. The name of the manufacturer is abbreviated as the manufacturer name. In the chart, "PE
"T" indicates a polyethylene terephthalate fiber.
"Ny" indicates a nylon fiber. “An” indicates an acrylic fiber. "R" indicates rayon fiber.
“Ar” indicates an aromatic amide fiber. "G" indicates a glass fiber. "CB" indicates carbon black. "M" indicates an intermetallic compound. “FY” indicates a long fiber. "SF" indicates short fiber. The denominator of fineness indicates the number of filaments.

The composite spinning is also called conjugate spinning, and it is a spinning for the purpose of simultaneously spinning two or more kinds of polymers having different physical properties from one hole to produce a fiber making the best use of each characteristic. Is the method. The kneading and spinning is a spinning method in which a specific substance is kneaded in a spinning step, and a conductive agent such as carbon black can be kneaded in producing a conductive fiber. The dispersion type is a material in which a conductive agent is dispersed and spun.

As the thread material 40 of this embodiment, "Mega III" shown in FIG. 5 can be preferably used. Only one type of functional fiber 24 can be used, or a plurality of types can be used. The following Table 1 shows the product name "Mega II
An example of physical characteristics when "IN" is used as the thread material 40 is shown.

[0035]

[Table 1]

FIG. 6 shows the type T-2 shown in Table 1 as the thread material 4
The cross-sectional structure when used as 0 is shown schematically. A layer of a conductive material 44 made of conductive carbon fine particles is formed around the core fiber 43 made of nylon 6 as a center. Such a structure can be formed by a composite spinning method, as also shown in FIG. Further, when the electrostatic flocking method as shown in FIG. 2 is used, a fiber having a conductive surface and an electrically insulating inside is more likely to fly.

Although a flocking roller has been conventionally manufactured by using a flocking technique, there are few materials having functionalities such as conductivity, and the method of use is limited. For example, in a conductive fiber manufactured by a conventional composite spinning method, an electrically insulating portion and a conductive portion are clearly separated on the surface of the fiber to form a single fiber. In such a structure, an electric field is electrostatically formed on the surface of the fiber, and the adhesive force due to the electric field increases. In addition, the exposed portion of the insulating portion on the surface of the fiber is large, and it is in a state in which electric charge is difficult to escape. Due to such an increase in adhesive force and residual electric charge, clogging is likely to occur, and it is necessary to deal with clogging spinning. Also,
In order to reduce the electric field on the surface, it is also used to coat the insulating fibers with a conductive coating material and then use the fibers for flocking. However, the use of this conductive coating material is not effective in an apparatus for which long life is required because it causes peeling due to abrasion, and needs improvement. In addition, when the fibers are jetted by an electric field to implant hair on the roller, the fibers are also affected by the electrical characteristics and cross-sectional shape of the fibers. If the electrical resistance value is too low, it becomes difficult to fly and the hair implant density decreases. There is a problem that will occur.

In the present embodiment, in order to improve these problems, as an improvement from the fiber itself, a fiber as shown in Table 1 in which the portion exposed on the surface by the composite spinning is made of an electric conductor is used. A fiber having an exposed portion of 50% or less is used. It is also possible to use fibers in which carbon black is uniformly dispersed or kneaded so that the resistance value of the fibers becomes a predetermined value. Even with low resistance fibers, the surface of the fibers can be treated so that they can fly easily and the flock density can be stabilized. When a thin film is formed on the surface of the fiber as a treatment, the flocking after the film formation can be performed, and the film can be removed by the post-treatment to stabilize the flocked density.

The surface of the supply roller 34 of this embodiment is made of the thread material 40, and if the thread material 40 is conductive, the material of the core material 41 is not only metal but also conductive resin or paper. It may be configured with any of The length of the thread member 40 can be 0.5 mm or more and 3 mm or less. As a characteristic of the flocked layer formed by the thread material 40, the length of the fiber tends to make the flocking level per unit area rough, and the shorter the fiber, the denser the flocking level becomes. The reason for this is that when the electrostatic flocking method as shown in FIG. 3 is adopted, the fibers are electrically blown. The thread material 40 is perpendicular to the outer peripheral surface of the core material 41.
The reason why the fibers adhere is that they tend to adhere in the fiber state where the electric field is the strongest. If the fibers of the thread material 40 are long, the fibers are likely to be entangled with each other when the fibers are moved by an electric field, and it is difficult for the fibers to be vertically attached to each other, resulting in a decrease in density. For example, as a result of a conventional evaluation of a toner supply roller in an actual machine, it has been found that when the length is about 2 mm, the toner supply property starts to decrease due to a decrease in the vertical fiber density. When the length of the fibers is 3 mm, the fibers are entangled with each other to be in a coarse state, and the flocked layer itself has a level of flocking that can be seen through, and the toner 32 can hardly be supplied. The fiber length is 0.
If it is less than 5 mm, on the contrary, the flocked layer becomes too dense and the surface becomes hard, and it is difficult to obtain elasticity, the torque increases, or there is no room for mechanical accuracy.

The single yarn resistance value of the thread material 40 is 10 ⁵ Ω / cm.
The range of -10 ¹² Ω / cm is preferable. When the resistance value is higher than 10 ¹² Ω / cm, electric charges remain on the thread material 40 and the toner 32 is likely to adhere to the thread material 40, and clogging and torque increase are likely to occur. If the resistance value is too high, frictional charging is likely to occur, the amount of charge of the toner 32 is increased, and the adhesive force to the thread material 40 is increased to easily cause clogging. Then, the insulating property of the supply roller 34 itself becomes high, and it becomes difficult to supply the toner 32 by the electric field. Further, when the resistance value is low, the voltage applied to the developing roller 33 (developing bias) is affected, and the resistance value that is too low is also a problem.

The single yarn decitex of the thread material 40 is preferably in the range of 1 decitex to 10 decitex. The decitex value is 1/10 of the tex value (tex: g / km), which is the weight of the fiber per unit length, and the larger the decitex value, the thicker the wire diameter and the stronger the rigidity of the developing roller 3.
3 is more likely to cause streak-like filming, and image defects are more likely to occur. Further, when the decitex value becomes small, the wire diameter becomes thin, the reset effect of the toner on the developing roller 33 by the supply roller 34 becomes weak, and the developing ghost phenomenon, which is the unevenness of the developing roller cycle, easily occurs. Therefore, it is necessary to set the wire diameter and the amount of bite into the developing roller 33 according to the material.

From the experience of the inventor of the present invention, 1.5
Denier (1.67 dtex) has a fiber length of 0.7
It has been found that mm to 1.5 mm is the usable area. At 7 denier (7.78 decitex),
It has been found that the usable range is from a fiber length of 1.2 mm to around 2.0 mm. It has also been found that the bite amount is preferably in the range of -0.1 mm to 0.7 mm. Minus sign means thread material 4
This means that the leading edge of 0 is far from the surface of the developing roller 33.

FIG. 7 shows a comparison between the supply roller 34 as the flocking roller according to the present embodiment and the conventional sponge roller with respect to the transition of the fog on the photosensitive member, which is remarkable in the sponge roller, with respect to the number of printed sheets. The supply roller 34 has a diameter of 15.7 mm, the thread member 40 is 3d (denier) and length 1.2 mm, and the core member 41 is made of stainless steel (SUS). The resistance value is 10 ⁷ Ω. There is. It can be seen that the flocking roller has improved fog on the photoconductor as compared with the sponge roller.

FIG. 8 shows the transition of the density difference between the leading end portion and the trailing end portion of the supply roller 34 and the sponge roller when printing a uniformly black "solid black" area. It can be seen that the flocking roller 34 is more stable. The supply roller 34 is
After printing 8000 sheets, the surface condition was not deteriorated, and the resistance value was maintained in the order of 10 ⁷ Ω, showing no significant change.

FIG. 9 shows the transition of the photoconductor fog density with respect to the number of printed sheets, with the amount (mm) of the feed roller 34, which is a flocking roller, eroding into the developing roller 33 as a parameter. The bite amount of − (minus) indicates that the surface of the thread material 40 is separated from the surface of the developing roller 33.

FIGS. 10 to 12 show various characteristics with the amount (mm) of the feed roller 34, which is a flocking roller, biting into the developing roller 33 as a parameter. FIG. 10 shows the fog density on the photoconductor after printing 1000 sheets, and FIGS. 11 and 12 show the followability of the supply roller 34 in terms of the image density and the density difference between the leading edge and the trailing edge of the “solid black”. And are shown respectively.

FIG. 13 shows a supply roller 3 which is a flocking roller.
4 shows the transition of the density difference from the "solid black" front end portion with respect to the number of printed sheets, with the amount (mm) of biting into the developing roller 33 of No. 4 as a parameter.

From FIG. 12 and the like, -0.4 is initially set.
It has been found that the bite amount of mm, that is, the tip end of the thread material 40 is not in contact with the developing roller 33, and the toner follows even if the distance is 0.4 mm. However, if the running is continued, the followability of the toner is deteriorated in the case of non-contact, and even if a predetermined density is obtained at the leading edge of the image, the density cannot be maintained at the trailing edge. Therefore, it can be said that non-contact is preferably limited to about 0.1 mm.

Good results are obtained when the bite amount is about 0.35 mm. That is, when a good result is obtained at 0 to 0.35 mm and the center is 0.35 mm,
It is estimated that good results can be obtained up to about 0.7 mm.

The dry non-magnetic one-component toner 32 used in this embodiment uses a polyolefin resin having a cyclic structure as a binder resin as disclosed in, for example, Japanese Patent Application Laid-Open No. 9-101631. Anything can be used. The toner disclosed in this publication contains a binder resin, a colorant and a charge control agent as main components.
The binder resin is a polyester resin, an epoxy resin, a polyolefin resin, a vinyl acetate resin, a vinyl acetate copolymer resin, a styrene acrylic resin, or another acrylic resin for 1 to 100 parts by weight of the cyclic polyolefin resin. It contains 0 to 99 parts by weight of at least one selected resin. The polyolefin resin having a cyclic structure has at least one functional group selected from a carboxyl group, a hydroxyl group, and an amino group, and has a structure crosslinked with an ionomer or a diene.

In the toner having such a binder resin, carbon black, diazo yellow, phthalocyanine blue, quinacridone, carmine 6B, monoazo red, perylene and the like can be used as a colorant. As the charge control agent, a nigrosine dye, a fatty acid-modified nigrosine dye, a metal-containing nigrosine dye, a mixed metal fatty acid-modified nigrosine dye, a chromium complex of 3.5-di-tert-gtylsalicylic acid, a quaternary ammonium salt, a triferrinylmethane dye , Azochrome complex and the like can be used.

As the toner, for example, JP-A-9-
A low molecular weight polyolefin wax as disclosed in Japanese Patent No. 43891 can also be included as a function-imparting agent. By including an olefin wax selected from a homopolymer of α-olefin, a copolymer of α-olefins and a copolymer of α-olefin and cycloolefin as a function-imparting agent, fixability, offset prevention property, heat resistance It is expected to improve responsiveness.

Further, a toner containing a cyclic polyolefin resin as a binder resin is disclosed in, for example, JP-A 2000-284.
As disclosed in Japanese Patent No. 528, as functionalizing agents, amide wax, carnauba wax, higher fatty acid and its ester, higher fatty acid metal soap, partially saponified higher fatty acid ester, higher aliphatic alcohol, polyolefin wax, paraffin It is also possible to include at least one wax selected from waxes.

Further, the toner 32 contains a cyclic olefin resin as a binder resin, and the developing roller 33 is provided with a blade 37 for regulating the layer thickness of the toner 32 attached on the outer peripheral surface. . Toner 32 containing a cyclic olefin resin as a binder resin is attached to the outer peripheral surface of the developing roller 33 to a thickness regulated by a blade 37, and is smoothly transferred from the developing roller 33 to the photosensitive drum 21 to perform development. You can

[0055]

As described above, according to the present invention, in the supply roller, one or a plurality of thread materials are planted on the outer peripheral surface of the roll-shaped core material, and the surface of the thread material is the surface of the developer carrier. If the conditions such as the electric field between the developer carrier and the supply roller, the speed ratio between the developer carrier and the supply roller, and the nip width (bite depth) are appropriate, the development from the supply roller is performed. The developer is supplied to the developing carrier, and the supplied developer is regulated to a predetermined developer layer thickness by a predetermined developer regulating member,
The developer whose layer thickness is regulated can be used for developing the electrostatic latent image bearing member in a developing area under a predetermined electric field.

According to the present invention, the length of the thread material is 0.5 m.
If the length of the thread material is long, the density of the thread material to be planted is reduced by the electrostatic flocking method, and if the length of the thread material is short, the electrostatic flocking method is used. Since the density of the thread material to be implanted increases, the density can be adjusted by the length of the thread material.

Further, according to the present invention, the single yarn decitex of the yarn material can be set within a range where an appropriate contact state can be obtained.

Further, according to the present invention, since the thread material is electrically conductive and also electrically conductive to the core material, it is possible to apply an electric charge from the supply roller to the developer which is in contact with the thread material.

Further, according to the present invention, since the single yarn resistance value of the thread material is in the range of 10 ⁵ Ω / cm or more and 10 ¹² Ω / cm or less, it is suitable for the developer which comes into contact with the thread material from the supply roller. Can be given an electric charge.

Further, according to the present invention, since the thread material is manufactured by the composite spinning method, it is possible to appropriately impart conductivity and mechanical properties.

Further, according to the present invention, the difference in the voltage applied between the developer carrying member and the supply roller can be maintained within a certain range, and the developer can be stably supplied.

Further, according to the present invention, it is possible to improve the image quality by keeping the speed ratio of the contact portion between the developer carrying member and the supply roller in the range of 0.5 times to 2.0 times.

Further, according to the present invention, the thread material of the developing roller is pushed into the surface of the developer carrying member within a range of not less than -0.1 mm and not more than 0.7 mm to supply the developer to the developer carrying member. Can be done smoothly.

[Brief description of drawings]

FIG. 1 is a simplified cross-sectional view showing a configuration of a main part of an image forming apparatus 20 including a developing device 30 according to an embodiment of the present invention.

FIG. 2 is a schematic front sectional view and a side sectional view of a supply roller 30 of FIG.

FIG. 3 is an exploded perspective view of the supply roller 30 of FIG.

4 is a table showing examples of conductive fibers that can be used as a thread material 40 in the supply roller 30 of FIG.

5 is a table showing examples of conductive fibers that can be used as a thread material 40 in the supply roller 30 of FIG.

FIG. 6 is a schematic cross-sectional view of the thread material 40 of FIG.

FIG. 7 is a graph showing a comparison between the supply roller 34 as a flocking roller according to the present embodiment and a conventional sponge roller with respect to the transition of the fog on the photoconductor, which is remarkable in the sponge roller, with respect to the number of printed sheets.

FIG. 8 is a graph showing a difference in density between the front end portion and the rear end portion when uniformly printing a black “solid black” area using the supply roller 34 as the flocking roller according to the present embodiment and the conventional sponge roller. It is a graph which compares and shows transition.

FIG. 9 is a graph showing a transition of the photoconductor fog density with respect to the number of printed sheets, using the amount (mm) of the feed roller 34 as a flocking roller according to the present embodiment as a bite into the developing roller 33 as a parameter.

FIG. 10 is a graph showing the fog density on the photoconductor after printing 1000 sheets, using the amount (mm) of the feed roller 34, which is a flocking roller, according to the present embodiment as a bite into the developing roller 33 as a parameter.

FIG. 11 shows the followability of the supply roller 34 at the leading edge and the trailing edge of the “solid black” with the amount (mm) of the feeding roller 34, which is the flocking roller, according to the present embodiment as the amount of bite into the developing roller 33. 3 is a graph showing the image density of

FIG. 12 shows the followability of the supply roller 34 between the leading edge and the trailing edge of the “solid black” with the amount (mm) of the feeding roller 34, which is the flocking roller, according to the present embodiment being bitten into the developing roller 33 as a parameter. It is a graph which shows about a density difference.

FIG. 13 is a graph showing a transition of the density difference from the leading edge of “solid black” with respect to the number of printed sheets, using the amount (mm) of the feed roller 34, which is a flocking roller, according to the present embodiment as a bite into the developing roller 33. .

FIG. 14 is a simplified cross-sectional view showing a configuration of a conventional electrophotographic image forming apparatus.

[Explanation of symbols]

20 image forming apparatus 21 Photosensitive drum 22 Charger 30 developing device 31 toner container 32 toner 33 developing roller 34 supply roller 35, 36, 38 DC power supply 37 blade 40 thread material 41 core material 42 adhesive 43 core fiber 44 Conductive material 49 AC power supply

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) D02G 3/44 G03G 15/08 507E (72) Inventor Park Hiroaki 232 Motoyani Shojiri, Anseong-si, Gyeonggi-do, Republic of Korea -7 In-fo-in F term (reference) 2H077 AC05 AD02 AD06 AD13 AD35 AE02 AE04 EA14 FA11 FA16 FA25 3B202 AA30 AB03 BA03 BC04 4L036 MA04 MA15 MA37 UA06

Claims (9)

[Claims] 1. A developer carrier for developing an electrostatic latent image with a nonmagnetic one-component developer for electrophotographic image formation, and a supply roller for supplying the developer to the developer carrier. In the developing device, the supply roller includes a roll-shaped core member, and one or a plurality of thread members that are planted on an outer peripheral surface of the core member and have a tip contacting the developer carrier. apparatus. 2. The thread material is flocked on the outer peripheral surface of the core material by an electrostatic flocking method, and the length of the thread material is in the range of 0.5 mm or more and 3 mm or less. The developing device according to claim 1. 3. The developing device according to claim 1, wherein the yarn material has a single yarn decitex in a range of 1 decitex or more and 10 decitex or less. 4. The developing device according to claim 1, wherein the thread material is electrically conductive and electrically conductive with the core material. 5. The yarn material has a single yarn resistance value of 10 ⁵ Ω / c.
5. The developing device according to claim 4, wherein the range is not less than 10 m and not more than 10 ¹² Ω / cm. 6. The developing device according to claim 5, wherein the thread material is a thread manufactured by a composite spinning method. 7. A power source for applying a voltage to each of the developer carrier and the supply roller is further included, and a difference between a voltage applied to the developer carrier and a voltage applied to the supply roller is 0 V or more and 350 V or less. The developing device according to claim 1, wherein 8. A portion of the developer carrying member that comes into contact with the supply roller moves to develop the electrostatic latent image, and the yarn is moved with respect to the speed at which the developer carrying member moves the supply roller. A developing device further comprising a rotating mechanism for rotationally driving so that a speed ratio of a tip portion of the material is in a range of 0.5 times or more and 2.0 times or less. 9. The supply roller is configured such that an amount of pushing the thread material into the surface of the developer carrying member is within a range of −0.1 mm or more and 0.7 mm or less with respect to the developer carrying member. The developing device according to claim 1, wherein the developing device is a developing device.